Multi-path interfolding apparatus

Abstract

An interfolding apparatus and method, utilize, first and second sheet-cutting-and-overlapping arrangements and an interfolding arrangement simultaneously mounted and operatively interconnected in a common frame, for alternatively selectively forming a first or a second interfolded pattern having a given folded width, without replacement of components of the interfolding apparatus. The first interfolded pattern is formed from a first stream of overlapped sheets of a first length cut from a web of sheet material fed along a first path extending through the first sheet-cutting-and-overlapping arrangement to the interfolding arrangement. The second interfolded pattern is formed from a stream of overlapped sheets of a second length cut from the web of sheet material fed along a second path extending through the second sheet-cutting-and-overlapping arrangement to the interfolding arrangement.

1. A multi-path interfolding apparatus, comprising, first and second sheet-cutting-and-overlapping arrangements and an interfolding arrangement, simultaneously mounted and operatively interconnected in a common frame, for alternatively selectively forming a first interfolded pattern having a folded width from overlapped sheets of a first length cut from a web of sheet material fed along a first path extending through the first sheet-cutting-and-overlapping arrangement to the interfolding arrangement, or forming a second interfolded pattern having the same folded width from overlapped sheets of a second length cut from the web of sheet material fed along a second path extending through the second sheet-cutting-and-overlapping arrangement to the interfolding arrangement. 
   
   
     2. The multi-path interfolding apparatus of  claim 1 , wherein:
 the interfolding apparatus is configured to move the streams of sheets through the interfolding arrangement at an interfolding feed speed (IFS); 
 the first sheet-cutting-and-overlapping arrangement is configured for generating a first overlap speed (FOS) which is higher than the interfolding feed speed (IFS); and 
 the second sheet-cutting-and-overlapping arrangement is configured for generating a second overlap speed (SOS) which is higher than the interfolding feed speed (IFS) and different from the first overlap speed (FOS). 
 
   
   
     3. The multi-path interfolding apparatus of  claim 2 , wherein:
 the first sheet length is substantially equal to a first length multiplier (FLM) of the folded width; and 
 the second sheet length is substantially equal to a second length multiplier (SLM) of the folded width. 
 
   
   
     4. The multi-path interfolding apparatus of  claim 3 , wherein:
 the first overlap speed (FOS) is the product of a first overlap multiplier (FOM) times the reciprocal of the first length multiplier (FLM) faster than the interfolding feed speed (IFS), substantially according to the formula [(FOS)=IFS (1+(FOM)(1/(FLM)))]; and 
 the second overlap speed (SOS) is the product of a second overlap multiplier (SOM) times the reciprocal of the second length multiplier (SLM) faster than the interfolding feed speed (IFS), substantially according to the formula, [(SOS)=IFS (1+(SOM)(1/(SLM)))]. 
 
   
   
     5. The multi-path interfolding apparatus of  claim 4 , wherein, at least one of the first and second length and overlap multipliers (FLM), (SLM), (FOM), (SOM) is an integer. 
   
   
     6. The multi-path interfolding apparatus of  claim 1 , wherein, at least one of the first and second sheet lengths is substantially equal to an integer multiple of the folded width. 
   
   
     7. The multi-path interfolding apparatus of  claim 1 , wherein:
 the first sheet-cutting-and-overlapping arrangement is configured for generating a stream of first sheets having a first sheet length; and 
 the second sheet-cutting-and-overlapping arrangement is configured for generating a stream of second sheets having a second sheet length different from the first sheet length. 
 
   
   
     8. The multi-path interfolding apparatus of  claim 7 , wherein, at least one of the first and second sheet lengths is substantially equal to an integer multiple of the folded width. 
   
   
     9. The multi-path interfolding apparatus of  claim 8 , wherein, both the first and second sheet lengths are substantially equal to integer multiples of the folded width. 
   
   
     10. The multi-path interfolding apparatus of  claim 1 , wherein, the interfolding arrangement includes a pair of interfolding rolls operatively mounted in the frame for rotation in opposite directions to one another and forming an interfolding nip therebetween, with the interfolding rolls being cooperatively configured to form an interfolded stack having the folded width from a stream of the first sheets fed along a first path extending through the interfolding nip, or alternatively to form an interfolded stack having the folded width from a stream of the second sheets fed along a second path extending through the nip. 
   
   
     11. The multi-path interfolding apparatus of  claim 10 , wherein:
 the interfolding rolls both rotate at the same speed and are of the same diameter, such that rotation of the interfolding rolls causes an interfolding roll peripheral speed (IFS); 
 the first sheet-cutting-and-overlapping arrangement comprises a first overlap roll rotatably mounted in the frame and having a rotational speed and diameter generating a first overlap roll peripheral speed (FOS) which is higher than the interfolding roll peripheral speed (IFS); and 
 the second sheet-cutting-and-overlapping arrangement comprises a second overlap roll rotatably mounted in the frame and having a rotational speed and diameter generating a second overlap roll peripheral speed (SOS) which is higher than the interfolding roll peripheral speed (IFS) and different from the first overlap roll peripheral speed (FOS). 
 
   
   
     12. The multi-path interfolding apparatus of  claim 11 , wherein:
 the first sheet-cutting arrangement further comprises a first-sheet-cutting-roll rotatably mounted in the frame and having a rotational speed and diameter generating a first-sheet-cutting-roll peripheral speed which is substantially equal to the first overlapping roll peripheral speed (FOS), the first sheet-cutting roll being configured for receiving the web of material and cutting the web into the first sheets at the first sheet length and delivering a stream of the first sheets along the first path to the first overlapping roll at a speed equal to the first overlapping roll peripheral speed (FOS); and 
 the second sheet-cutting arrangement further comprises a second-sheet-cutting-roll rotatably mounted in the frame and having a rotational speed and diameter generating a second-sheet-cutting-roll peripheral speed which is substantially equal to the second overlapping roll peripheral speed (SOS), the second sheet-cutting roll being configured for receiving the web of material and cutting the web into the second sheets at the second sheet length and delivering a stream of the second sheets along the second path to the second overlapping roll at a speed equal to the second overlapping roll peripheral speed (SOS). 
 
   
   
     13. The multi-path interfolding apparatus of  claim 12 , wherein:
 the first sheet length is substantially equal to a first length multiplier (FLM) of the folded width; and 
 the second sheet length is substantially equal to a second length multiplier (SLM) of the folded width. 
 
   
   
     14. The multi-path interfolding apparatus of  claim 13 , wherein:
 the first overlap roll peripheral speed (FOS) is the product of a first overlap multiplier (FOM) times the reciprocal of the first length multiplier (FLM) faster than the interfolding roll peripheral speed (IFS), substantially according to the formula [(FOS)=IFS (1+(FOM)(1/(FLM)))]; and 
 the second overlap roll peripheral speed (SOS) is the product of a second overlap multiplier (SOM) times the reciprocal of the second length multiplier (SLM) faster than the interfolding roll peripheral speed (IFS), substantially according to the formula, [(SOS)=IFS (1+(SOM)(1/(SLM)))]. 
 
   
   
     15. The multi-path interfolding apparatus of  claim 14 , wherein, at least one of the first and second length and overlap multipliers (FLM), (SLM), (FOM), (SOM) is an integer. 
   
   
     16. A multi-path interfolding method, comprising:
 simultaneously mounting and operatively connecting first and second sheet-cutting-and-overlapping arrangements and an interfolding arrangement in a common frame to form an interfolding apparatus; and 
 alternatively selectively forming a first interfolded pattern having a folded width from overlapped sheets of a first length cut from a web of sheet material fed along a first path extending through the first sheet-cutting-and-overlapping arrangement to the interfolding arrangement, or forming a second interfolded pattern having the same folded width from overlapped sheets of a second length cut from the web of sheet material fed along a second path extending through the second sheet-cutting-and-overlapping arrangement to the interfolding arrangement. 
 
   
   
     17. The multi-path interfolding method of  claim 16 , further comprising:
 threading the web of material through the first cutting-and-overlapping arrangement; and 
 operating the first cutting-and-overlapping arrangement and the interfolding arrangement to form the first interfolded pattern of overlapped first sheets. 
 
   
   
     18. The multi-path interfolding method of  claim 17 , further comprising:
 unthreading the web of material from the first cutting-and-overlapping arrangement and the interfolding arrangement; then 
 threading the web of material through the second cutting-and-overlapping arrangement; and then 
 operating the second cutting-and-overlapping arrangement and the interfolding arrangement to form the second interfolded pattern of overlapped second sheets. 
 
   
   
     19. The multi-path interfolding method of  claim 17  further comprising, shutting down the second cutting-and-overlapping arrangement while operating the first cutting-and-overlapping arrangement and the interfolding arrangement to form the first interfolded pattern of overlapped first sheets. 
   
   
     20. The multi-path interfolding method of  claim 17 , wherein, the second cutting-and-overlapping arrangement utilizes a vacuum for manipulating the second sheets as they travel along the second path, and the method further comprises, shutting off the vacuum to the second sheet-cutting-and-overlapping arrangement during operation of the first cutting-and-overlapping arrangement and the interfolding arrangement to form the first interfolded pattern of overlapped first sheets. 
   
   
     21. A multi-path interfolding apparatus comprising:
 first and second sheet-cutting-and-overlapping arrangements and an interfolding arrangement, simultaneously mounted and operatively interconnected in a common frame, for alternatively selectively forming a first interfolded pattern having a folded width from overlapped sheets of a first length cut from a web of sheet material fed along a first path extending through the first sheet-cutting-and-overlapping arrangement to the interfolding arrangement, or forming a second interfolded pattern having the same folded width from overlapped sheets of a second length cut from the web of sheet material fed along a second path extending through the second sheet-cutting-and-overlapping arrangement to the interfolding arrangement; 
 the interfolding arrangement including, a pair of interfolding rolls of substantially the same diameter operatively mounted for rotation in opposite directions to one another at the same rotational speed to thereby generate a substantially identical interfolding roll peripheral speed (IFS); 
 the pair of interfolding rolls forming an interfolding nip therebetween, with both the first and second paths extending through the interfolding nip, the interfolding rolls being cooperatively configured to form an interfolded stack having the folded width from the stream of the first sheets fed along the first path extending through the interfolding nip, or alternatively to form an interfolded stack having the folded width from the stream of the second sheets fed along a second path extending through the nip; 
 the first sheet-cutting-and-overlapping arrangement including a first overlap roll rotatably mounted in the frame and having a rotational speed and diameter generating a first overlap roll peripheral speed (FOS) which is faster than the interfolding roll peripheral speed (IFS); 
 the second sheet-cutting-and-overlapping arrangement including a second overlap roll rotatably mounted in the frame and having a rotational speed and diameter generating a second overlap roll peripheral speed (SOS) which is faster than the interfolding roll peripheral speed (IFS) and faster than the first overlap roll peripheral speed (FOS); 
 the first sheet-cutting-and-overlapping arrangement also including a first sheet cutting arrangement mounted in the frame for receiving and cutting the web of material to generate and deliver a stream of the first sheets along the first path to the first sheet-cutting-and-overlapping arrangement at a first cut-sheet speed substantially equal to the first overlap roll peripheral speed (FOS); 
 the second sheet-cutting-and-overlapping arrangement also including a second sheet-cutting arrangement mounted in the frame for receiving and cutting the web of material to generate and deliver a stream of the second sheets along the second path to the second sheet-cutting-and-overlapping arrangement at a second cut-sheet speed substantially equal to the second overlap roll peripheral speed (SOS). 
 
   
   
     22. The multi-path interfolding apparatus of  claim 21 , wherein:
 the first sheet-cutting arrangement further comprises a first-sheet-cutting-roll rotatably mounted in the frame and having a rotational speed and diameter generating a first-sheet-cutting-roll peripheral speed which is substantially equal to the first overlap roll peripheral speed (FOS), the first sheet-cutting roll being configured for receiving the web of material and cutting the web into the first sheets at the first sheet length and delivering a stream of the first sheets along the first path to the first overlap roll at a speed equal to the first overlap roll peripheral speed (FOS); and 
 the second sheet-cutting arrangement further comprises a second-sheet-cutting-roll rotatably mounted in the frame and having a rotational speed and diameter generating a second-sheet-cutting-roll peripheral speed which is substantially equal to the second overlap roll peripheral speed (SOS), the second sheet-cutting roll being configured for receiving the web of material and cutting the web into the second sheets at the second sheet length and delivering a stream of the second sheets along the second path to the second overlap roll at a speed equal to the second overlap roll peripheral speed (SOS). 
 
   
   
     23. The multi-path interfolding apparatus of  claim 22 , wherein:
 the first sheet length is substantially equal to a first length multiplier (FLM) of the folded width; and 
 the second sheet length is substantially equal to a second length multiplier (SLM) of the folded width. 
 
   
   
     24. The multi-path interfolding apparatus of  claim 23 , wherein:
 the first overlap roll peripheral speed (FOS) is the product of a first overlap multiplier (FOM) times the reciprocal of the first length multiplier (FLM) faster than the interfolding roll peripheral speed (IFS), substantially according to the formula [(FOS)=IFS (1+(FOM)(1/(FLM)))]; and 
 the second overlap roll peripheral speed (SOS) is the product of a second overlap multiplier (SOM) times the reciprocal of the second length multiplier (SLM) faster than the interfolding roll peripheral speed (IFS), substantially according to the formula, [(SOS)=IFS (1+(SOM)(1/(SLM)))]. 
 
   
   
     25. The multi-path interfolding apparatus of  claim 24 , wherein, at least one of the first and second length and overlap multipliers (FLM), (SLM), (FOM), (SOM) is an integer. 
   
   
     26. The multi-path interfolding apparatus of  claim 25 , wherein:
 the first sheet length is substantially equal to three times the folded width; 
 the second sheet length is substantially equal to four times the folded width; 
 the first overlapping roll peripheral speed (FOS) is one third faster than the interfolding roll peripheral speed (IFS); and 
 the second overlapping roll peripheral speed (SOS) is one half faster than the interfolding roll peripheral speed (IFS).